EFIDynoTuning Forum

Is there a fuel pressure sensor i can use other than the oem unit? My rails don't have provisions for the sensor and i was hoping i could use something like the AEM lab grade sensor and simply plot the pressure voltages in the tune. Since i am planning on running boost should i just use a regulator?

Aftermarket sensors don't measure injection pressure they measure rail pressure so it wouldn't be ideal to use them. All fuel systems require a regulator of some sorts that has nothing to do with the rail pressure sensor.

My understanding of the ford pwm pump systems is there is a controlled leak after the pump inside the tank (orifice) which allows the pump to bleed down and the computer varies the pwm signal to maintain pressure. AFAIK, There is no mechanical regulation. Is that not accurate? CAn you explain what the difference between injection pressure vs rail pressure? Im not sure I understand the difference.

no thats wrong

rail pressure is exactly that -the pressure of the fuel rail
injection pressure is the actual delta pressure that the injector sees
http://efidynotuning.com/inj.htm

on returnless fuel systems 1999-2010 the regulator is mounted in the tank and is better know as the PPRV. Positive pressure relief valve. It pops off between 65psi and 90psi to prevent over pressurizing the injectors if there was a fault. It also acts as the regulator when the fuel rail pres sensor fails as the ecu powers the pump and cant do any trimming.

On returnless setups the pump voltage is modulated to deliver a desired delta pressure from the frps. It can only control pressure below the pprv.

On the 2011 coyotes on up ford swapped back to the earlier 98 and older return style fuel system. They kept the PPRV in the tank instead of mounting it on the rail that way they dont need a return line and they dont use a frps since its not returnless. They kept the fpdm and give the pump half voltage at idle and low loads.

Thanks for the explanation. I had the ford system all wrong.

Is there any way to regulate pump voltage using RZASA? I would really like to be able to ramp the pump voltage using the pwm feature with a SS relay based on load. I dont mind putting a regulator in the back to control the pressure. Im really looking at ways of minimizing heat transfer to the fuel. If I can minimize fuel recirculating that will help significantly. With the high altitude here, fuel boils pretty easy so im trying to plan ahead.

yes just simple wire up an fpdm and rail pressure sensor and control it like stock. You need a pump designed for pwm like a stock coyote pump that I recommend. Simply toss a regulator next to the tank with the pressure set to 65psi and just control pressure with the ecu.

From my understanding, the 340lph is a turbine pump which AFAIK will work with PWM. Ill probably use that since I have an almost new 340lph im about to pull out of my car. Also, do i want a crown vic fpdm or one from an 2011+ 'yote, wasnt sure if I could run the one from the new mustang?

no the crown vic one is better